# Difficulty at cutting a phase in a roof to create hole for staircase. Help

Hi

I’m working on a two storey house.

I have created walls, ceilings, openings, etc. Now, I need to create the opening on the ground floor to create the staircase but I can’t seem to create the hole. I have made a rectangle on the roof of the ground floor, but when I try to cut it to make the hole, nothing happens. I’m wondering if it’s because the ceiling is a group. But could I ungroup it?
I’d like to attach the picture for you guys to see.

Thanks

Paula

Floorplan 1.zip (755.7 KB)

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If you have made the floor into a group or component and you want to cut a hole in it by using Push/Pull, you need to open the group/component first. There are other ways, but that’s the simplest.

We can’t tell how you have grouped things or what the elements look like as you have not uploaded the file.

BTW, what is a “phase” in this context?

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There’s no need to explode (ungroup) the ceiling group.
Simply right context click on the group > Edit Group

See this video tutorial
Groups and Components

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Thank you.

Hi Dave

Hi Simon

Thanks.

Er…I don’t think you have. Either it was too big or you’ve done something wrong. How did you do it?

Oh, I see, you’ve added it to the original post. Sorry.

OK, well there are several issues here.

Number one, your floor has no thickness, it is just a flat plane without depth. So you can’t use Push/Pull.

Secondly, you have an odd grouping structure with elements nested inside other elements and none of them named. That will likely lead to confusion. This is where Outliner comes in useful as you can see the structure.

I recommend that you start by simplifying the nested groups. Then, when you have the floor as a distinct group, go into it and give the floor some thickness using Push Pull. Then draw a rectangle on one surface representing the stairwell and Push Pull to create the opening. Then close the group and get rid of what you have drawn above the floor (which presumably does not represent anything).

And get used to naming your groups so they make sense when reading Outliner. Some folk don’t use groups and only use components. When you create a component SU encourages you to name it (though it does offer a generic default name). That seems like a bore at first but it only takes a moment (if you keep it simple but unique) and you soon get used to doing it.

Just noticed another issue. Your floor is not flat. Look at the Z axis dimensions on this screenshot. This will create all kinds of problems unless it was intentional.

Thank you so much.
I will follow every step you have mentioned.

I return your drawing with some amendments. The floor is now level and has a depth of 200mm. The stairwell has been cut out. And I have exploded your nesting so that all your floor elements are in one group which I have named Floor.

There are quite a few other things that I would want to tidy up but as I am not sure what your end goal is, I haven’t done any of them.

Floorplan 1.skp (858.2 KB)

There must be a scaling issue going on as well. The main block of your building is about 50 x 100m! That is why a floor depth of 200mm looks so thin.

Very silly but probably important question, what does ‘nested groups mean’? I know it’s talked in outliner a lot but I can’t quite understand it.

It is an important question, you’re right.

If you take your original drawing and look at it in Outliner you may see that you have a group with a right pointing grey triangle next to it. That means there are level below it which will be revealed if you click on the triangle. If you select your floor group you will see that there are two levels in a hierarchical order below. That means you have one group within another all within the top level one. I don’t suppose you meant to do that but it can be hard to know exactly where you are in a drawing if you are not aware of the nesting.

The nesting is there for a reason. Say you wanted to draw a door. You might make it a component. The door component might then create sub-components like glass, door handle, rails, panels, etc. The door hadle might itself be composed of sub-elements and so you start building a nested component.

This is what your drawing looked like before I changed it:

Oh what a very thorough explanation. Thank you so much.

You’re welcome.

Another handy tip about Outliner is that it works both ways. What I mean is that if you select something in the drawing, it will get highlighted in Outliner. Equally, if you select something in Outliner, it shows up on the drawing. So if you do have stray groups or components, you can identify them in Outliner (perhaps just because they have no proper name) and you can see in the drawing what hey relate to. then you can decide what to do with them, such as giving them a unique name, exploding them, deleting them, or adding them to another group.

You are using layers incorrectly, you should read up on them here.
Controlling Visibility with Layers | SketchUp Knowledge Base

PS: in future, upload the .skp file not the .skb file
If less than 3mb attach it directly rather than zipping it.
Larger than 50mb use dropbox or similar.

Thank you. I will

I think the house i’m working on (a course i’m taking to learn how to use sketchup) has different layers and the tutor never explained how to achieve the thickness of the floor so I clearly made a mistake not knowing how far back I needed to go to fix it. Now, he’s doing the staircase and I didn’t know how he attached the first floor to the ground floor. So I will definitely check the outliner all the time now.

Thanks Simon.

Not sure what you mean by attaching that. Everyone has a different way of working but I would probably have each floor separate and unconnected. But you could have all the floors in a floor group if you wanted.

It seems a bit odd for your tutor to be moving on to something detailed like a staircase if his students still have some basic drawing organisation to get to grips with. The staircase will definitely need a group or component of its own! Has he suggested what grouping you might need? I would have at least the following for a house:

External walls
Internal walls
Floors
Roof
Stairs
Windows
Doors
Kitchen units
Sanitary fittings
Furniture

There are likely to be sub-groups within each of those.

Since as @Box noted, you aren’t using SketchUp layers correctly, I’d be a bit wary about the expertise of the course instructor!